Spinal rod extenders and methods of use

A spinal rod assembly comprising:

• an elongated rod extending along a first longitudinal axis and including first and second ends and an outer surface extending therebetween;
• a coupler including a first coupling feature and a second coupling feature, the first coupling feature including a receiver section with a channel formed by a back wall and spaced-apart side walls that extend away from the back wall and terminate at ends, the channel having an open side opposite from the back wall and between the ends of the side walls to accept the outer surface of the elongated rod laterally into the receiver section, and the second coupling feature comprising a post extending away from the first coupling feature along a second longitudinal axis substantially perpendicular to the first longitudinal axis;
• and
• an extender rod including a third coupling feature formed to engage the post of the second coupling feature, and an elongated extender rod body extending from the third coupling feature along a third longitudinal axis,
• the first coupling feature including a first degree of rotational freedom and a first degree of translational freedom in positioning the coupler relative to the first longitudinal axis, and the second and third coupling features cooperating to include at least a second degree of rotational freedom in positioning the extender rod about the second longitudinal axis;
• the post of the second coupling feature sized to fit within an aperture in the third coupling feature such that the post extends across the third longitudinal axis when engaging the aperture;
• and
• the elongated rod and the elongated extender rod body each having a length to span a plurality of vertebrae.